Insecticide formulations

ABSTRACT

The present invention relates to novel liquid formulations for the controlled and sustained release of insecticidally active compounds by means of a heat source and the water-based pre-solutions required for preparing these formulations.

The present invention relates to novel liquid formulations for thecontrolled and sustained release of insecticidally active compounds bymeans of a heat source and the pre-solutions required for preparingthese formulations. The novel insecticidal formulations for thecontrolled and sustained release of insecticidally active compounds arecharacterized in that they comprise transfluthrin as insecticide andmore than 90% of water as solvent.

Electrical heating devices, for example so-called tablet vaporizers, forkilling insects, for example mosquitos, are known from the prior art. Inthis method, suitable materials, such as, for example, pulp and cottoncardboard, asbestos, ceramic and/or porous artificial resins areimpregnated with insecticidally active compound solutions to obtaininsecticide tablets. The insecticides are volatilized by the action of aheating device generating temperatures of 120-190° C.

A considerable disadvantage of these tablet vaporizers is theunfavorable ratio of energy input to amount of active compound to bevaporized, since the proportion of active compound in relation to theauxiliaries is low. Furthermore, owing to factors inherent in thesystem, i.e. the high operating temperature and the mode of action ofthese vaporizers, the active compounds are released in a very nonuniformmanner over the prescribed duration of action. The duration of action ofthese vaporizer tablets is limited to a maximum of 12 hours. Finally,the unfavorable ratio of active compound to active compound carrierpermanently requires a relatively large supply of vaporizer tablets,resulting in a considerable consumption of material.

Vaporizing devices for domestic use as described in GB 2 153 227, wherethe vaporization of an insecticidally active compound solution iseffected by means of a heated wick and where the active compound isdissolved in a mixture of saturated aliphatic hydrocarbons which isvaporized electrically by using the wick, have been known for some time.

The amount of organic solvent required in these so-called liquidvaporizers, which is considerable in relation to the amount of activecompound, results in a high indoor solvent concentration when theproduct is used.

This in turn causes walls and objects in the vicinity of these devicesto become soiled, which is often complained about by users.

A decisive disadvantage of the formulations used in these devices is thefact that their use leads to permanently high concentrations of organicsubstances, such as saturated hydrocarbons, in the room air, which, forhealth reasons, is becoming less and less desirable.

A further disadvantage of these formulations is the risk of theflammable solvents leaking, leading to considerable problems duringtransport and storage and hazards during use.

The object of the present invention was to formulate insecticidallyactive compounds in such a way that they are not only storage-stable butcan also, in addition to this, be vaporized undecomposed in combinationwith organic and inorganic auxiliaries, emulsifiers, solublilizers,stabilizers, antioxidants, perfumes and colorants from physiologicallyacceptable solutions in a uniform way and over a prolonged period bymeans of a heat source. The vaporization is to be carried out using acommercially available vaporizing device where a physiologicallyacceptable solution is absorbed by a suitable wick and released into theatmosphere by heating the upper part of this suitable wick.

The present invention thus relates to liquid formulations forvaporization using electric vaporizers fitted with a wick not having thedisadvantages of the prior art owing to water being used as solvent.Since water is used as solvent, the formulations according to theinvention are not flammable, and organochemical substances are releasedinto the room air to a much lesser extent. This method for vaporizing anaqueous insecticidal solution can be employed for killing insects, suchas, for example, mosquitos or moths.

In addition, the aqueous formulations according to the invention aresimple to use in commercially available liquid vaporizers at the normalvaporizing temperatures of 100 to 160° C., and they ensure a continuousrelease of the active compound for up to 60 days, preferably up to 45days.

The formulations according to the invention include formulationscomprising insecticides, for example transfluthrin, water as solvent andone or more organochemical substances suitable as emulsifiers and/orco-surfactant. In addition, organic or inorganic auxiliaries,stabilizers, perfumes and/or colorants can be added to the mixtures.

The formulations according to the invention are prepared for example byinitially preparing a pre-solution of transfluthrin, emulsifier and, ifappropriate, co-surfactant which is then diluted to the desired emulsionvolume by vigorous mixing with small portions of water. Furtheradditives, perfumes and colorants can be admixed either to thepre-solution or to the ready-made-up diluted emulsion.

Alternatively, the formulations according to the invention can beobtained by directly mixing the individual components in succession.

The active compound transfluthrin is particularly suitable for theformulations according to the invention and applications thereof sinceit can be emulsified particularly well in the manner stated and inaddition possesses the high thermal stability necessary for theapplication, so that, during vaporization, no decomposition productsinterfering with the transport process through the wick and thevaporization from the upper end of the wick are formed.

Other active compounds, such as, for example, d-allethrin orbioallethrin, which are conventionally used in liquid vaporizer systemshave long been known to be poorly emulsifiable and to have the tendencyto decompose when heated and to form decomposition products blocking thewick.

Suitable emulsifiers are, for example:

nonionic emulsifiers, such as reaction products of unsubstituted orsubstituted phenols, respectively optionally unsaturated or saturatedfatty alcohols, fatty acids, fatty acid alkanolamides or fatty amines,vegetable oils or fats, partial fatty acid esters of polyols withethylene oxide and, if appropriate, propylene oxide, sorbitan esters offatty acids, fatty acid esters of polyols such as sucrose, glucose orsorbitan,

anionic emulsifiers, such as respectively optionally saturated orunsaturated alkanesulfonates, alkyl sulfates, alkyl phosphates, alkylether sulfates, alkyl ether phosphates, salts of fatty acids, alkylether carboxylates, acyltaurides or acylsarcosides, each of whichcontains 8 to 22 carbon atoms,

cationic emulsifiers, such as amine salts, quaternary ammonium compoundsor imidazolinium compounds, each of which contains 8 to 22 carbon atoms,

amphoteric emulsifiers, such as betaines, sulfobetaines or amine oxides,each of which contains 8 to 22 carbon atoms.

Preferred emulsifiers are:

reaction products of 4-50, in particular 8-30, mol of ethylene oxideand, if appropriate, propylene oxide with phenols (1 mol) substituted byone or more radicals (C₁-C₁₂)-alkyl, (C₃-C₆)-cycloalkyl-, phenyl-,phenyl-(C₁-C₃)-alkyl-, or methylphenyl-(C₁-C₃)-alkyl and reactionproducts of 5-50, in particular 8-30, mol (per equivalent of fattyradical) of ethylene oxide and, if appropriate, propylene oxide with(C₁₀-C₂₂)-fatty alcohols, fatty acids or fatty acid glycerides.

The aqueous formulations may additionally preferably also comprisealkali metal salts and/or alkaline earth metal salts of(C₁₀-C₂₀)-alkanesulfonic acids, in particular dodecylbenzenesulfonicacid, as further emulsifiers.

Particular preference is given to the following emulsifiers, which canbe used on their own or in a mixture:

Emulsifier 1371 A (67% of alkylarylsulfonate, 23% of n-butanol, CAS # 90194-26-6), a linear calcium arylsulfonate dissolved in n-butanol:

Emulsifier 1371 B (100% of fatty acid polyethylene glycol ether esters,CAS # 61791-12-6), a reaction product of castor oil with 20-40 mol ofethylene oxide,

Emulsifier 368 pure (100% of aryl polyglycol ether, CAS # 73297-33-3) ofthe following formula:

Emulsifier PS 16 (100% of aryl polyglycol ether, CAS # 104376-75-2) ofthe following formula:

Emulsifier PS 29 (100% of aryl polyglycol ether, CAS # 104376-75-2) ofthe following formula:

Emulsifier L7 (100 of fatty alcohol polyglycol ether, CAS # 68213-23-0)of the following formula:

CH₃—(CH₂)₁₁-₁₇—O—(CH₂—CH₂O)₇—H

Reaction products of optionally unsaturated fatty alcohols, containing12-18 carbon atoms, with 6-15, in particular 7-10, mol of ethyleneoxide,

if appropriate in combination with alkali metal salts and/or alkalineearth metal salts of (C₁₀—C₂₀)-alkanesulfonic acids, in particulardodecylbenzenesulfonic acid.

Examples of co-surfactants include:

straight-chain or branched alcohols having 3 to 10 carbon atoms,cycloalkanols having 5 to 8 carbon atoms, (C₂—C₆)-alkyl esters of(C₂—C₆)-hydroxycarboxylic acids, (C₁—C₁₂)-alkylpyrrolidones,(C₁—C₁₂)-alkylcaprolactams, cyclohexylpyrrolidone orcyclohexylcaprolactam, N,N-dimethyl- orN,N-diethyl-(C₄—C₁₂)-carboxamides, benzyl alcohol and high boilingmineral oils.

Preferred co-surfactants are:

aliphatic (C₃—C₈)-alcohols, cyclohexanol, methylcyclohexanol,(C₃—C₄)-alkyl lactates, cyclohexylpyrrolidone, octylpyrrolidone,decylpyrrolidone, dodecylpyrrolidone, dimethylamides of octanoic acid,decanoic acid and undecanoic acid, or high boiling mineral oils.

It is possible to add colorants to the formulations according to theinvention, for example:

inorganic pigments, for example iron oxide, titanium oxide and PrussianBlue,

organic dyestuffs, such as alizarin, azo dyestuffs and metalphthalocyanine dyestuffs,

and trace nutrients such as salts of iron, manganese, boron, copper,cobalt, molybdenum and zinc.

These additions of colorants to the formulations according to theinvention facilitate the identification of the liquid in the storagecontainer and can also be used for visual identification of the endpoint of the biological effectiveness of the system.

A variant of the visual end point identification using added colorantsmay also take the form of a change in color when the active compoundsand water have evaporated.

Deodorants, such as, for example, lauryl methacrylate, geranylcrotonate, acetophenone myristate, p-methylacetophenone benzaldehyde,benzyl acetate, benzyl propionate, amyl cinnamaldehyde, anisaldehyde,diphenyl oxide, methyl benzoate, ethyl benzoate, methylphenyl acetate,ethylphenyl acetate, neoline, safrole, and the like, may be added to theformulations according to the invention.

Other substances which can furthermore be added to the formulationsaccording to the invention are natural perfumes such as, for example,musk, civet, ambergris, castoreum and similar perfumes; ajowa oil,almond oil, absolute of amberseed, angelica root oil, aniseed oil, basiloil, bay oil, benzoin resinoid, essence of bergamot, birch oil, rosewoodoil, absolute of common broom, cajeput oil, cananga oil, capsicum oil,caraway oil, cardamom oil, carrot seed oil, cassia oil, cedar wood oil,celery seed oil, cinnamon bark oil, citronella oil, clary sage oil,clove oil, cognac oil, coriander oil, cubeb oil, camphor oil, dill oil,taragon oil, eucalyptus oil, sweet fennel oil, galbanum resinoid, garlicoil, geranium oil, ginger oil, grapefruit oil, hop oil, absolute ofhyacinth, absolute of jasmine, juniper berry oil, labdanum resinoid,lavender oil, bay leaf oil, lemon oil, lemon grass oil, lovage oil, maceoil, mandarin oil, absolute of mimosa, absolute of myrrh, mustard oil,absolute of narcissus, neroli -oil, nutmeg oil, absolute of oak moss,olibanum resinoid, onion oil, opoponax resinoid, orange oil, orangeflower oil, concrete iris, pepper oil, peppermint oil, Perubalsam,petitgrain oil, pine needle oil, absolute of rose, rose oil, rosemaryoil, sandalwood oil, sage oil, spearmint oil, storax oil, thyme oil,balsam of tolu, absolute of tonka bean, absolute of tuberose, turpentineoil, absolute of vanilla pod, vetiver oil, absolute of violet leaves,ylang-ylang oil and similar vegetable oils and the like.

Synthetic perfumes which can be added to the formulations according tothe invention are:

pinene, limonene and similar hydrocarbons; 3,3,5-trimethylcyclohexanol,linalool, geraniol, nerol, citronellol, menthol, bomeol,borneylmethoxycyclohexanol, benzyl alcohol, anisyl alcohol, cinnamylalcohol, phenylethyl alcohol, cis-3-hexanol, terpineol and similaralcohols; anetholes, musk xylene, isoeugenol, methyleugenol and similarphenols; amylcinnamaldehyde, anisaldehyde, n-butyraldehyde,cuminaldehyde, cydlamenaldehyde, decyl aldehyde, isobutyraldehyde,hexaldehyde, heptaldehyde, n-nonyl aldehyde nonadienol, citral,citronellal, hydroxycitronellal, benzaldehyde, methylnonyl acetaldehyde,cinnamaldehyde, dodecanol, hexylcinnamaldehyde, undecanal, heliotropin,vanillin, ethylvanillin, and similar aldehydes, methyl amyl ketone,methyl naphthyl ketone, methyl nonyl ketone, musk ketone, diacetyl,acetylpropionyl, acetylbutyryl, carvone, methone, camphor, acetophenone,p-methylacetophenone, ionone, methylionone and similar ketones;amyl-butyrolactone, diphenyl oxide, methylphenyl glycidate,nonylacetone, coumarin, cineol, ethylmethylphenyl glycidate and similarlactones or oxides, methyl formate, isopropyl formate, linalyl formate,ethyl acetate, octyl acetate, methyl acetate, benzyl acetate, cinnamylacetate, butyl propionate, isoamyl acetate, isopropyl isobutyrate,geranyl isovalerate, allyl caproate, butyl heptylate, octyl caprylate,methyl heptinecarboxylate, methyl octinecarboxylate, isoamyl caprylate,methyl laurate, ethyl myristate, methyl myristate, ethyl benzoate,benzyl benzoate, methylcarbinylphenyl acetate, isobutylphenyl acetate,methyl cinnamate, styracin, methyl salicylate, ethyl anisate, methylanthranilate, ethyl pyruvate, ethyl butylbutyrate, benzyl propionate,butyl acetate, butyl butyrate, p-tert-butylcyclohexyl acetate, cedrylacetate, citronellyl acetate, citronellyl formate, p-cresyl acetate,ethyl butyrate, ethyl caproate, ethyl cinnamate, ethylphenyl acetate,ethylene brassylate, geranyl acetate, geranyl formate, isoamylsalicylate, isoamyl valerate, isobornyl acetate, linolyl acetate, methylanthranilate, methyl dihydrojasmonate, nonyl acetate, phenylethylacetate, trichloromethylenephenylcarbinyl acetate, terpinyl acetate,vetiveryl acetate and similar esters.

These perfumes can be used on their own, or it is possible to use atleast two thereof as a mixture with each other. In addition to perfume,the formulation according to the invention can, if appropriate,additionally comprise the additives conventionally used in the perfumeindustry, such as patchouli oil or similar volatilization inhibitors,such as eugenol, or similar viscosity regulators.

The formulations according to the invention generally comprise between0.01 and 95% by weight of transfluthrin, preferably between 0.1 and 10%by weight.

The formulations according to the invention further comprise between0.01 and 20% by weight, preferably between 0.01 and 5% by weight, ofemulsifier and, if appropriate, between 0.01 and 20% by weight,preferably between 0.01 and 5% by weight, of one or more co-surfactant.

The pre-solutions used in the preparation generally comprise between 10and 70% by weight of transfluthrin, preferably between 15 and 40% byweight.

The pre-solutions further comprise between 10 and 70% by weight,preferably between 15 and 40% by weight, of emulsifier and, ifappropriate, between 10 and 60% by weight, preferably between 20 and 45%by weight, of co-surfactant.

The preparation, compositions and the properties of the novelinsecticidal formulations according to the invention are illustrated bythe examples below.

EXAMPLE 1

Preparation of the pre-solutions

The emulsifier and the active compound are initially charged andhomogenized by stirring at room temperature for 10 minutes. After thehomogenization, the co-surfactant and, if appropriate, water are slowlyadded with stirring at room temperature.

In this manner, the pre-solutions below were prepared:

Example No. Component Percentage 1.1. Transfluthrin 43.0%N-Octylpyrrolidone 40.0% Emulsifier 368 pure 8.5% Emulsifier PS 29 8.5%1.2. Transfluthrin 45.0% N-Octylpyrrolidone 40.0% Emulsifier 368 pure7.5% Emulsifier PS 29 7.5% 1.3. Transfluthrin 26.6% N-Octylpyrrolidone25.0% Emulsifier 368 pure 10.0% Isopropanol 1.0% Water 37.4% 1.4.Transfluthrin 40.0% Emulsifier 368 pure 30.0% 1-Butanol 10.0% Water20.0% 1.5. Transfluthrin 30.0% Emulsifier 368 pure 40.0% 1-Butanol 30.0%1.6. Transfluthrin 40.0% Marlowet OFA* 20.0% Isopropanol 20.0% 1.7.Transfluthrin 40.0% Emulsifier 368 pure 40.0% Isopropanol 20.0% 1.8.Transfluthrin 40.0% Emulsifier 1371 B 26.7% Isopropanol 33.3% 1.9.Transfluthrin 40.0% Emulsifier 1371 B 40.0% Isopropanol 20.0%  1.10.Transfluthrin 19.40% Emulsifier L7 3.70% Emulsifier 368 7.30% Na ABSsolution (10%) 2.20% Isopropanol 0.80% N-Octylpyrrolidone 22.60% Water44.0%  1.11. Transfluthrin 20.0% Emulsifier L7 4.50% Emulsifier 3689.00% Na ABS solution (10%) 4.50% Isopar V 20.00% N-Octylpyrrolidone23.00% Water 19.00%  1.12. Transfluthrin 30.00% Emulsifier 1371 A 10.00%Emulsifier L7 15.00% Isopar V 40.00% Water 5.0%  1.13. Transfluthrin17.00% Emulsifier 1371 A 10.00% Emulsifier L7 15.00% Isopar V 51.00%Water 7.0% *Marlowet OFA is a surfactant mixture comprising:triethanolamine salts of C₁₀-C₁₃-alkylbenzenesulfonic acid ethoxylatedoleic acid triethanolamine and ethoxylated dodecanol

EXAMPLE 2

Preparation of the insecticidal vaporizer solutions

The pre-solution is initially charged. The calculated amount ofdemineralized water is added in small portions with vigorous mixing,forming an opalescent emulsion.

In this manner, the following solutions were prepared:

Example No. Component Percentage 2.1.  Transfluthrin  1.00%N-Octylpyrrolidone  0.93% Emulsifier 368 pure  0.20% Emulsifier PS 29 0.20% Water 97.67% 2.2.  Transfluthrin  1.00% N-Octylpyrrolidone  0.89%Emulsifier 368 pure  0.19% Emulsifier PS 29  0.19% Water 97.73% 2.3. Transfluthrin  0.40% Emulsifier 1371 B  0.20% Isopropanol  0.50% Water98.90% 2.4.  Transfluthrin  0.40% Emulsifier 1371 B  0.30% Isopropanol 0.50% Water 98.80% 2.5.  Transfluthrin  0.40% Emulsifier 1371 B  0.40%Isopropanol  0.50% Water 98.70% 2.6.  Transfluthrin  0.80% Emulsifier1371 B  0.60% Isopropanol  0.50% Water 98.10% 2.7.  Transfluthrin  0.40%Emulsifier 1371 B  0.20% Isopropanol  0.50% Water 98.90% 2.8. Transfluthrin  0.80% Emulsifier 1371 B  0.70% Isopropanol  0.50% Water98.00% 2.9.  Transfluthrin  0.80% Emulsifier 1371 B  0.80% Isopropanol 0.50% Water 97.90% 2.10. Transfluthrin  1.00% Emulsifier 1371 B  0.50%Isopropanol  0.50% Water 98.00% 2.11. Transfluthrin  1.00% Emulsifier1371 B  0.60% Isopropanol  0.50% Water 97.90% 2.12. Transfluthrin  1.00%Emulsifier 1371 B  0.70% Isopropanol  0.50% Water 97.80% 2.13.Transfluthrin  1.00% Emulsifier 1371 B  0.80% Isopropanol  0.50% Water97.70% 2.14. Transfluthrin  1.00% Emulsifier 1371 B  0.90% Isopropanol 0.50% Water 97.60% 2.15. Transfluthrin  1.00% Emulsifier 1371 B  1.00%Isopropanol  0.50% Water 97.50% 2.16  Transfluthrin  1.00% Emulsifier368 pure  0.34% N-Octylpyrrolidone  0.94% Isopropanol  0.04% Water97.68% 2.17. Transfluthrin  1.00% Emulsifier 1371 B  1.32% 1-Butanol 0.33% Water 97.35% 2.18. Transfluthrin  0.80% Emulsifier 1371 B  0.80%Isopropanol  0.40% Water 98.00% 2.19. Transfluthrin  1.00% Emulsifier1371 B  0.67% Isopropanol  0.83% Water 97.50% 2.20. Transfluthrin  0.70%Emulsifier 1371 B  1.00% Benzyl alcohol  4.00% Isopropanol 25.00%Butylhydroxytoluene  1.00% Water 68.30% 2.21. Transfluthrin  0.50%Butylhydroxytoluene  1.00% Diethylene glycol 52.50% monobutyl etherWater 46.00% 2.22. Transfluthrin  0.70% Butylhydroxytoluene  1.00%Diethylene glycol 58.30% monobutyl ether Water 40.00% 2.23.Transfluthrin  1.50% Butylhydroxytoluene  1.00% Diethylene glycol 51.50%monobutyl ether Water 46.00% 2.24. Transfluthrin  0.80% Emulsifier L7 0.15% Emulsifier 368  0.30% Na ABS solution (10%)  0.09% Isopropanol 0.03% N-octylpyrrolidone  0.93% Water 97.70% 2.25. Transfluthrin  0.80%Emulsifier L7  0.18% Emulsifier 368  0.36% Na ABS solution (10%)  0.18%Isopar V  0.80% N-Octylpyrrolidone  0.92% Water 96.76% 2.26.Transfluthrin  0.80% Emulsifier 1371 A  0.27% Emulsifier L7  0.40%Isopar V  1.07% Water 97.46% 2.27  Transfluthrin  0.82% Emulsifier 1371A  0.49% Emulsifier L7  0.73% Isopar V  2.47% Water 95.49%

EXAMPLE 3

Release characteristics of the insecticidal vaporizer solutionsaccording to the invention

Examples 3.1 to 3.3 show the evaporation characteristics of an exemplaryinsecticidal formulation according to the invention using various wicksystems. The evaporation rates are shown in mg/h and the cumulativeamounts evaporated are stated in percent.

What is claimed is:
 1. An insecticidal formulation comprising: a)transfluthrin; b) one or more emulsifiers; c) one or more co-surfactantsselected from the group consisting of straight-chain or branchedalcohols having 3 to 10 carbon atoms, cycloalkanols having 5 to 8 carbonatoms, C₂—C₆-alkyl esters of C₂—C₆-hydroxy-carboxylic acids,C₁—C₁₂-alkylpyrrolidones, C₁—C₁₂-alkylcaprolactams,cyclohexylpyrrolidone or cyclohexylcaprolactam, N,N-dimethyl- orN,N-diethyl-(C₄—C₁₂)-carboxamides, benzyl alcohol and high boilingmineral oils; and d) water.
 2. The insecticidal formulation according toclaim 1, which comprises at least one of organic or inorganicauxiliaries, stabilizers, perfumes and colorants.
 3. The insecticidalformulation according to claim 1, which comprises one or moreemulsifiers independently selected from the group consisting of nonionicemulsifiers, anionic emulsifiers, cationic emulsifiers and amphotericemulsifiers.
 4. The insecticidal formulation according to claim 3,wherein the nonionic emulsifiers are selected from the group consistingof reaction products of unsubstituted or substituted phenols, optionallyunsaturated or saturated fatty alcohols, fatty acids, fatty acidalkanolamides or fatty amines, vegetable oils or fats, partial fattyacid esters of polyols with ethylene oxide and, optionally, propyleneoxide, sorbitan esters of fatty acids, and fatty acid esters of polyols;the anionic emulsifiers are selected from the group consisting ofoptionally saturated or unsaturated alkanesulfonates, alkyl sulfates,alkyl phosphates, alkyl ether sulfates, alkyl ether phosphates, salts offatty acids, alkyl ether carboxylates, acyltaurides and acylsarcosides,each of which contains 8 to 22 carbon atoms; the cationic emulsifiersare selected from the group consisting of amine salts, quaternaryammonium compounds and imidazolinium compounds, each of which contains 8to 22 carbon atoms; and the amphoteric emulsifiers are selected from thegroup consisting of betaines, sulfobetaines and amine oxides, each ofwhich contains 8 to 22 carbon atoms.
 5. The insecticidal formulationaccording to claim 1, which comprises at least one emulsifier which is areaction product of 4-50 mol of ethylene oxide and optionally propyleneoxide with phenols (1 mol) which are substituted by one or more radicalsof (C₁—C₁₂)-alkyl, (C₃—C₆)-cycloalkyl-, phenyl-, phenyl (C₁—C₃)-alkyl-,and/or methylphenyl-(C₁—C₃)-alkyl and/or a reaction product of 5-50 mol(per equivalent of fatty acid radical) ethylene oxide and optionallypropylene oxide with (C₁₀—C₂₂)-fatty alcohols, fatty acids or fatty acidglycerides.
 6. The insecticidal formulation according to claim 1, whichcomprises at least one of colorants, deodorizing agents and natural orsynthetic perfumes.
 7. The insecticidal formulation according to claim1, which comprises 0.01 to 95% by weight of transfluthrin based on thetotal weight of the formulation.
 8. The insecticidal formulationaccording to claim 4, which comprises 0.01 to 20% by weight ofemulsifier based on the total weight of the formulation.
 9. Theinsecticidal formulation according to claim 1, which comprises more than90% by weight of water based on the total weight of the formulation. 10.A process for preparing an insecticidal formulation according to claim1, said process comprising preparing a pre-solution comprising saidtransfluthrin, said one or more emulsifiers and said co-surfactants, andthen diluting said pre-solution to a desired formulation volume byvigorous mixing of said pre-solution with small portions or water.
 11. Apre-solution for preparing an insecticidal formulation according toclaim 1, said pre-solution comprising: a) 10-70% by weight oftransfluthrin; b) 10-70% by weight of total emulsifier; and c) 10-60% byweight of total co-surfactant, wherein the total co-surfactant consistsof one or more co-surfactants selected from the group consisting ofstraight-chain or branched alcohols having 3 to 10 carbon atoms,cycloalkanols having 5 to 8 carbon atoms, C₂—C₆-alkyl esters ofC₂—C₆-hydroxy-carboxylic acids, C₁—C₁₂-alkylpyrrolidones,C₁—C₁₂-alkylcaprolactams, cyclohexylpyrrolidone orcyclohexylcaprolactam, N,N-dimethyl- orN,N-diethyl-(C₄—C₁₂)-carboxamides, benzyl alcohol and high boilingmineral oils.